Boride ceramics as one of modern high-tech materials, due to the high melting point, high hardness, high oxidation resistance and wear resistance performance and as a hard tool materials, abrasive, corrosion resistant alloy additive, wear-resisting parts, at the same time the material and it has excellent electric properties, as inert electrode materials and high temperature electrical material and attaches great importance to by the people.
Introduction and application of boride ceramic materials
Introduction of boride ceramic materials
Boride ceramics belong to interspace phase compounds, and their chemical bond composition is relatively complex, including m-M metal bond, B-B covalent bond and B-M ionic bond, which determines that boride has a variety of characteristics from the microscopic level. At present, boride cermets are widely used in the coating field, such as binary, ternary and polyboride. The main preparation techniques are APS(atmospheric plasma spraying), HVOF(supersonic flame spraying), plasma cladding, laser cladding, argon arc cladding, induction cladding, vapor deposition and magnetron sputtering.
Among boride ceramics, SiB6, ZrB2, HfB2, TiB2, CrB, WB/WB2 are considered as the most promising boride ceramics due to their excellent properties. Binary boride ceramic materials are cost-effective and have excellent mechanical and physical and chemical properties. As functional materials, SiB6, ZrB2, HfB2, TiB2, CrB2 and other boride ceramics are widely used in wear resistance, corrosion resistance coatings, neutron absorption coatings and self-melting alloys, as well as ultra-high temperature coatings. In the steel industry, can be used for stainless steel coating.
Application of binary boride ceramics
SiB6 belongs to orthonormal system, space group Pnnm, and has calcium hexaboride cubic crystal structure. At present, SiB6 can be synthesized by elemental reaction and chemical vapor deposition. Sintering methods generally have no pressure sintering, hot pressing sintering, reaction hot pressing sintering and put point plasma sintering method. SiB6 ceramics have excellent thermoelectric properties, high strength, high melting point and low density, excellent high-temperature oxidation resistance, high hardness and wear resistance, and are a potential P-type semiconductor materials. At present, it is mainly used for thermal radiation coating, various standard abrasives and grinding cemented carbide. Also used as engineering ceramic materials, sandblasting nozzle, the manufacture of gas engine blades and other special-shaped sintered parts and seals, can also be used as anti-oxidant refractory materials.
Product name: silicon hexaboride
Molecular formula: SiB6
Specifications: 8 μm, -200 mesh
Melting point: 2540 ℃, 2200 ℃
ZrB2 can be used as a protective tube for continuous temperature measurement of molten metal crucible, armor plate and iron and steel industry. In addition, it can be used as an electronic device to prepare conductivity and electrical contact materials, double heating electrode of continuous casting tundish and thermocouple protective tube under harsh conditions. As a structural material, ZrB2 can be used as high temperature resistant material, corrosion resistant material, wear resistant material and super hard material, such as corrosion and wear resistant electroplating coating, underwater nozzle and nozzle material, due to its high melting point, high hardness, good electromagnetic properties and high corrosion resistance.
Product name: Zirconium diboride
Molecular formula: ZrB2
Specifications: 100 nm, 500 nm, 3-5 μm
Purity: 99% +
Melting point: 3500 ℃
HfB2 hafnium boride is a gray metallic crystal. By hafnium dioxide and boron oxide or boron carbide, carbon powder mixed heating or by the hafnium tetrachloride and boron trichloride at 2000℃ hydrogen reduction or hafnium and boron direct reaction prepared. Hafnium boride ceramic material has excellent properties such as melting point, high thermal conductivity, high hardness, high chemical stability and good high temperature strength, which can be used for thermal protection components such as hypersonic aircraft, rocket propulsion, atmospheric re-entry aircraft and strategic missiles. In addition, hafnium boride ceramic materials can also be used as high temperature refractory materials, electrode materials.
Name: Hafnium diboride
Molecular formula: HfB2
Melting point: 3250 ℃
TiB2 can be used as cathode or cathode coating of aluminum electrolytic cell, and can be used to prepare high current electrode, guide rail and armature due to its excellent electric conductivity and thermal conductivity and not reacting with aluminum liquid and crcrite. TiB2 can also be used for vacuum evaporation of metal film evaporation boat or container, integrated circuit, film capacitor, optical device film, aluminum paper or plastic and glass metal coating, etc. In military application, TiB2 can be widely used in military armor materials due to its high elastic modulus. TiB2 has good electrical conductivity and stable chemical properties, which can be used to prepare anti-impurity diffusion layer of active metals and electromagnetic shielding and anti-stress diffusion components in ASL temperature calibration instrument. Because of its high hardness, high strength and high stability, TiB2 can be used in aviation, automobile and tool industries to prepare bulletproof body, all kinds of wear and corrosion resistant roller table, lining plate, valve, fan, pipe, pipe fittings, mold, cutting tools and ultra-high temperature refractory materials, such as missile nozzle and high temperature engine parts.
Product name: Titanium boride powder
Molecular formula: TiB2
Size: 3-5 μm
Melting point: 3140 ℃
Density: 4.930 g/mL
CrB2 chromium diboride is a very hard metallic compound with excellent wear resistance and high temperature resistance. It has good thermal earthquake resistance, strong acid resistance and high neutron absorption cross section under 1300℃. It is widely used in abrasion resistance, corrosion resistance coating, neutron absorption coating and self-melting alloy for strengthening hard phase.
Product name: Chromium diboride
Molecular formula: CrB2
Size: -325 mesh
Melting point: 1550 °C